378 



NATURE 



[Feb. 20, 1879 



We learn from the Annual Report of the Moscow University 

 that the number of students at the University was, during 1878, 

 1,643, with 108 professors ; 318 of them were in the Jurispru- 

 dence Faculty, 131 in the Philological, 240 in the Physico-Mathe- 

 matical, and 954 studied Medicine. No less than 62 medical 

 students have taken part in the last war ; the majority of students 

 are very poor, and 417 of them received pecuniary help which 

 has reached, during the year, the sum of 11,500/. 



SCIENTIFIC SERIALS 



'' American yournal of Science and Arts, January, 1879. — Prof. 

 Loomis's important paper in this number on storms on the 

 Atlantic, &c., has been noticed elsewhere. Prof. Marsh (in an 

 appendix) describes a new order of extinct reptiles [Sauranodontd) 

 from the Jurassic formation of the Rocky Mountains ; they 

 closely resemble Ichthyosaurus (of which no remains have 

 hitherto been found in America), but are without teeth. The 

 same author continues his " Principal Characters of American 

 Jurassic Dinosaurs." — Prof. Greene, of Troy, New York, de- 

 scribes a paper dome constructed from his plans for an astro- 

 nomical observatory. The paper covering is in sixteen equal 

 sections, the framework of each section consisting of three ribs 

 of pine meeting at the apex. There are also a circular sill at 

 the base and two parallel semicircular arch girders spanning 

 the dome (all of pine). The entire structiu-e weighs about 4,000 

 lbs. The dome is supported on six 8-inch balls rolling between 

 grooved iron tracks by direct pre=sure. — Mr. Edison describes 

 his tasimeter as applied to measuring the heat of the stars and of 

 the sun's corona. — Mr. Fontaine writes on the mesozoic strata of 

 Virginia, and Mr. Holden on the brightness and stellar magni- 

 tude of the third Saturnian satellite. — A list of fifty specie-; of 

 east coast fishes (many of them new to the fauna) is supplied by 

 Messrs. Goode and Blan. — In the "Miscellaneous Intelligence" 

 will be found the report of the committee appointed to consider 

 the scientific surveys of the United States territories. 



SOCIETIES AND ACADEMIES 

 London 



Royal Society, January 23. — " On the Microrheometer." 

 By J. B. Hannay, F.R.S.E., F.C.S., lately Assistant Lecturer 

 on Chemistry in the Owens College, Manchester. Communicated 

 by H. E. Roscoe, LL.D., F.R.S., Professor of Chemistry in 

 Owens College, Manchester, 



In this paper the author reviews the work done by chemists 

 and physicists in determining the relation between the chemical 

 composition of a liquid and its rate of flow through a capillary 

 tube. Poiseiulle » ascertained, in a very accurate manner, all 

 the physical laws relating to the rate of flow, as regulated by 

 temperature, pressure, and dimensions of the tube ; but on 

 examining saline solutions he could make nothing of the numbers 

 presented, because he used percentage solutions instead of solu- 

 tions proportional to the equivalent of the body dissolved. 

 Graham,* noticing that Poiseiulle had discovered a hydrate of 

 alcohol by running various mixtures of alcohol and water through 

 the tube, examined mixtures of the various acids with water, 

 and found that the hydration proceeded by distinct steps of 

 multiple proportions. Several others, notably Guerout,^ have 

 since worked on the same subject, but as they have only worked 

 on organic liquids, and have done all the rates at the same tem- 

 perature, the results throw no light on the phenomena. Thus 

 water runs about five times as quickly at 100° as at 0° ; and in 

 a series of alcohols, such as Guerout experimented upon, the 

 differences between their boiling points were very great, so that, 

 their vapour tensions or molecular mobilities being quite incom- 

 parable while at the same temperature, the experiments do not 

 admit of any real interpretation. The author reserves the 

 organic part of the investigation, which requires the determina- 

 tion of vapour tensions, till a future paper, and in the present 

 deals with saline solutions. 



The phenomenon of the flow of liquids through capillary tubes 

 has been called in this country transpiration, while in other 

 countries no distinct name has been adopted ; and as the English 

 word is already in use in French for another purpose, and pro- 

 perly applies to gases (the laws relating to which are quite 

 different), the author proposes to use for liquids the term 



» Attn, de Ckim. et de Physique, [3], t, vii. 5a. 



= Phil Trans., 1861, p. 373. 



3 Comptes Rendus, ixxix. p. 1201 ; Ixxxi, p. 1025. 



"Microrheosis," from p.iKp{s and ^e'oi, the instrument being called 

 the microrheometer. The form of apparatus which the author 

 finally adopted is figured in the paper, and is so arranged that 

 when the liquid is introduced, as many experiments as may be 

 desired may be tried, and the pressure and temperature, as well 

 as the atmosphere in which the experiment is conducted, may be 

 varied, while the thermometer indicating the temperature is 

 at the mean point of the system. The author gives a curve 

 for water from 0° to 100°, the differences of rate being smaller 

 as the temperature rises. 



Various salts are then examined, being dissolved to form 

 "normal" solutions; but as the solubility of some salts is too 

 low for such solutions, the effect of the amount of salts dissolved 

 is determined. This is found to be directly proportional to the 

 amount of salt in solution. Values for many salts in solution 

 are then given, each number being the mean of ten experiments, 

 and the probable-error of the mean is calculated in each case. 

 The conclusions arrived at are these. The rate of flow does not 

 depend on any of the ' ' mechanical " features of the salt, such as 

 crystalline form, specific volume, solubility, &c.; but upcn the 

 mass of the elements forming the substance and the amount of 

 energy expended in its formation. Each element has a value of 

 its own, which is continued in all its compounds. Thus all the 

 salts of potassium and sodium formed by the same acids have a 

 constant difference. In like manner each metalloid and acid 

 radicle has a value which is continued in all its combinations. 

 Then the greater the combining value of an element the quicker 

 is its microrheosis ; thus potassium has a higher rate than sodium, 

 barium than strontium, strontium than calcium, and so on. The 

 microrheosis also varies with the amount of energy in the com- 

 pound ; thus nitrates stand highest, as they contain most energy ; 

 then chlorides; and, lastly, sulphates, which are exhausted 

 compounds. 



The instrument, bringing to light as it does the fundamental 

 relations of combining weight and energy in chemical action, 

 will be of the utmost importance in chemical physics, as by its 

 use not only will the amount of energy evolved in reactions be 

 determined, but the mass combined; or, in other words, the 

 chemical equivalent of the elements involved will be found. 



February 6. — "On certain Dimensional Properties of Matter 

 in the Gaseous State." By Osborne Reynolds, F.R.S., Pro- 

 fessor of Engineering at Owens College. 



Mathematical Society, February 13.— C. W. Merrifield, 

 F.R.S., president, in the chair. — Sir J. Cockle, F.R.S., way 

 admitted into the Society. — Mr. R. Hargreaves and Prof. W. 

 E. Story were proposed for election.— Dr. Hirst, F.R.S., com- 

 municated a paper by M. Halphen on the number of conies 

 which satisfy five independent conditions. — Sir J. Cockle spoke 

 upon a construction for making magic squares. Messrs. Cayley, 

 Harley, Henrici, Roberts, Hart, and other gentlemen took part 

 in a discussion on the subject. Prof. Henrici, F.R.S., i;ave 

 some properties of frames. — Prof. H. J. S. Smith, F.K.S.» 

 read two papers on a modular equation and on the formula for 

 four Abelian functions. — Mr. J. J. Walker communicated a qua- 

 ternion proof of Minding's theorem. 



Linnean Society, February 6.— Prof. AUman, F.R.S., 

 president, in the chair. — Mr. J. R. Jackson exhibited specimens 

 from the tombs of ancient Thebes. Among these were fruits of 

 the Doum Palm (Hyphcene thebaica) and of H. aigun, formerly, 

 but wrongly, described as an Areca. Small berries also obtained 

 were identified as those of Juniperus phcenicea as against those of 

 y. excelsa. — Mr. J. G. Baker showed dried bulbs of Buphane- 

 toxicarea, which furnish a principal ingredient of the poison the 

 Bushmen of South Africa tip their arrows with. Structurally, 

 the numerous tunics of the bulb are a peculiarity. The range 

 of this plant has been found to be as far north as Lake Tan- 

 ganyika. In Sir C. W. Strickland's hothouse a plant flowered 

 last year, and this for the first time in England. — Mr. W. T. 

 Thiselton Dyer shortly described specimens of, and pointed out 

 the special characters and probable advantages of, a new fodder 

 grass, Euchlana luxurians, and he also exhibited and made 

 remarks on curious instrmnents used for weaving fibre of Curcu- 

 ligo laUfolia by the natives of Borneo. — Mr. T. Christy drew 

 attention to a sample of tea grown in Natal, and to a bottle of 

 the milky secretion of the African Rubber Tree (Landolphia), 

 the same having been freshly drawn from the living plant and 

 inamediately thereafter forwarded to this country ; slight coagula- 

 tion of the juice had nevertheless occurred. — The Rev. G. 

 Henslow passed round for examination a specimen of female:. 



